1. Field of the Invention
The present invention relates to a rechargeable battery, and more particularly, to a collecting plate of a rechargeable battery.
2. Description of the Background
Unlike nonrechargeable batteries that are incapable of being recharged, rechargeable batteries may be charged repeatedly. Recently, high-power rechargeable batteries that use a non-aqueous electrolyte that has high energy density have been used. Low capacity rechargeable batteries that have one battery cell that is packaged into a pack are used in small portable electronic devices such as cellular phones, laptop computers, and camcorders. High capacity rechargeable batteries that have numerous battery cells connected in series or in parallel are used as a power source for driving motors such as in hybrid electronic vehicles.
A rechargeable battery may have various shapes such as cylindrical, rectangular box, and pouch shapes. The rechargeable battery comprises an electrode assembly including a positive electrode, a negative electrode, and a separator interposed therebetween. The electrode assembly is wound spirally (like a jelly roll) and inserted into a case. The case is provided with a cap assembly having external terminals.
The positive electrode and negative electrode of the rechargeable battery are provided with conductive tabs to collect a current that is generated by an electrode assembly during operation of the battery and to transfer the current to the external terminals.
When a rechargeable battery is used in a high power device, the aforementioned tabs may be replaced with a collecting plate to reduce resistance of a current collecting portion. A rechargeable battery that uses the collecting plate is disclosed in U.S. Pat. No. 6,193,765.
When a typical rechargeable battery is shaken due to external impact or an interval problem, the collecting plate may become detached from the electrode assembly or the case. Furthermore, the collecting plate may be damaged or broken.
In the conventional rechargeable battery, since there is a clearance between the electrode assembly and the case to which the collecting plate is fixed, the electrode assembly may be shaken. The shaking may deteriorate the connection between the collecting plate and the electrode assembly. Furthermore, the collecting plate may become detached from the electrode assembly or the case causing a malfunction in the rechargeable battery.
In particular, if the rechargeable battery is used as a large capacity rechargeable battery for a vacuum cleaner, an electric scooter, an electric vehicle, or a hybrid vehicle, an external impact or internal vibration may be continuously exerted on the rechargeable battery thus, exacerbating the problem.
In particular, welded portions of the electrode assembly may become increasingly fatigued due to the continuous impact or vibration causing the collecting plate to be detached from the fixed portions.